<?php // $Id: tablelib.php,v 1.24.2.5 2008/05/22 02:33:56 jerome Exp $

define('TABLE_VAR_SORT',   1);
define('TABLE_VAR_HIDE',   2);
define('TABLE_VAR_SHOW',   3);
define('TABLE_VAR_IFIRST', 4);
define('TABLE_VAR_ILAST',  5);
define('TABLE_VAR_PAGE',   6);

class flexible_table {

	var $uniqueid		= NULL;
	var $attributes	  = array();
	var $headers		 = array();
	var $columns		 = array();
	var $column_style	= array();
	var $column_class	= array();
	var $column_suppress = array();
	var $column_nosort   = array('userpic');
	var $setup		   = false;
	var $sess			= NULL;
	var $baseurl		 = NULL;
	var $request		 = array();

	var $is_collapsible = false;
	var $is_sortable	= false;
	var $use_pages	  = false;
	var $use_initials   = false;

	var $maxsortkeys = 2;
	var $pagesize	= 30;
	var $currpage	= 0;
	var $totalrows   = 0;
	var $sort_default_column = NULL;
	var $sort_default_order  = SORT_ASC;
	
	/**
	 * Constructor
	 * @param int $uniqueid
	 * @todo Document properly
	 */
	function flexible_table($uniqueid) {
		$this->uniqueid = $uniqueid;
		$this->request  = array(
			TABLE_VAR_SORT	=> 'tsort',
			TABLE_VAR_HIDE	=> 'thide',
			TABLE_VAR_SHOW	=> 'tshow',
			TABLE_VAR_IFIRST  => 'tifirst',
			TABLE_VAR_ILAST   => 'tilast',
			TABLE_VAR_PAGE	=> 'page'
		);
	}
	
	/**
	 * Sets the is_sortable variable to the given boolean, sort_default_column to 
	 * the given string, and the sort_default_order to the given integer.
	 * @param bool $bool
	 * @param string $defaultcolumn
	 * @param int $defaultorder
	 * @return void
	 */
	function sortable($bool, $defaultcolumn = NULL, $defaultorder = SORT_ASC) {
		$this->is_sortable = $bool;
		$this->sort_default_column = $defaultcolumn;
		$this->sort_default_order  = $defaultorder;
	}

	/**
	 * Do not sort using this column
	 * @param string column name
	 */
	function no_sorting($column) {
		$this->column_nosort[] = $column;
	}

	/**
	 * Is the column sortable?
	 * @param string column name, null means table
	 * @return bool
	 */
	function is_sortable($column=null) {
		if (empty($column)) {
			return $this->is_sortable;
		}
		if (!$this->is_sortable) {
			return false;
		}
		return !in_array($column, $this->column_nosort);
	}

	/**
	 * Sets the is_collapsible variable to the given boolean.
	 * @param bool $bool
	 * @return void
	 */
	function collapsible($bool) {
		$this->is_collapsible = $bool;
	}

	/**
	 * Sets the use_pages variable to the given boolean.
	 * @param bool $bool
	 * @return void
	 */
	function pageable($bool) {
		$this->use_pages = $bool;
	}

	/**
	 * Sets the use_initials variable to the given boolean.
	 * @param bool $bool
	 * @return void
	 */
	function initialbars($bool) {
		$this->use_initials = $bool;
	}

	/**
	 * Sets the pagesize variable to the given integer, the totalrows variable
	 * to the given integer, and the use_pages variable to true.
	 * @param int $perpage
	 * @param int $total
	 * @return void
	 */
	function pagesize($perpage, $total) {
		$this->pagesize  = $perpage;
		$this->totalrows = $total;
		$this->use_pages = true;
	}

	/**
	 * Assigns each given variable in the array to the corresponding index
	 * in the request class variable.
	 * @param array $variables
	 * @return void
	 */
	function set_control_variables($variables) {
		foreach($variables as $what => $variable) {
			if(isset($this->request[$what])) {
				$this->request[$what] = $variable;
			}
		}
	}

	/**
	 * Gives the given $value to the $attribute index of $this->attributes.
	 * @param string $attribute
	 * @param mixed $value
	 * @return void
	 */
	function set_attribute($attribute, $value) {
		$this->attributes[$attribute] = $value;
	}

	/**
	 * I think that what this method does is set the column so that if the same data appears in 
	 * consecutive rows, then it is not repeated.
	 * 
	 * For example, in the quiz overview report, the fullname column is set to be suppressed, so
	 * that when one student has made multiple attempts, their name is only printed in the row
	 * for their first attempt.
	 * @param integer $column the index of a column.
	 */
	function column_suppress($column) {
		if(isset($this->column_suppress[$column])) {
			$this->column_suppress[$column] = true;
		}
	}

	/**
	 * Sets the given $column index to the given $classname in $this->column_class.
	 * @param integer $column
	 * @param string $classname
	 * @return void
	 */
	function column_class($column, $classname) {
		if(isset($this->column_class[$column])) {
			$this->column_class[$column] = ' '.$classname; // This space needed so that classnames don't run together in the HTML
		}
	}

	/**
	 * Sets the given $column index and $property index to the given $value in $this->column_style.
	 * @param integer $column
	 * @param string $property
	 * @param mixed $value
	 * @return void
	 */
	function column_style($column, $property, $value) {
		if(isset($this->column_style[$column])) {
			$this->column_style[$column][$property] = $value;
		}
	}

	/**
	 * Sets all columns of the given $property to the given $value in $this->column_style.
	 * @param integer $property
	 * @param string $value
	 * @return void
	 */
	function column_style_all($property, $value) {
		foreach(array_keys($this->columns) as $column) {
			$this->column_style[$column][$property] = $value;
		}
	}

	/**
	 * Sets $this->reseturl to the given $url, and $this->baseurl to the given $url plus ? or &amp;
	 * @param type? $url
	 * @return type?
	 */
	function define_baseurl($url) {
		$this->reseturl = $url;
		if(!strpos($url, '?')) {
			$this->baseurl = $url.'?';
		}
		else {
			$this->baseurl = $url.'&amp;';
		}
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function define_columns($columns) {
		$this->columns = array();
		$this->column_style = array();
		$this->column_class = array();
		$colnum = 0;

		foreach($columns as $column) {
			$this->columns[$column]		 = $colnum++;
			$this->column_style[$column]	= array();
			$this->column_class[$column]	= '';
			$this->column_suppress[$column] = false;
		}
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function define_headers($headers) {
		$this->headers = $headers;
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function make_styles_string(&$styles) {
		if(empty($styles)) {
			return '';
		}

		$string = ' style="';
		foreach($styles as $property => $value) {
			$string .= $property.':'.$value.';';
		}
		$string .= '"';
		return $string;
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function make_attributes_string(&$attributes) {
		if(empty($attributes)) {
			return '';
		}

		$string = ' ';
		foreach($attributes as $attr => $value) {
			$string .= ($attr.'="'.$value.'" ');
		}

		return $string;
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function setup() {
		global $SESSION, $CFG;

		if(empty($this->columns) || empty($this->uniqueid)) {
			return false;
		}

		if (!isset($SESSION->flextable)) {
			$SESSION->flextable = array();
		}

		if(!isset($SESSION->flextable[$this->uniqueid])) {
			$SESSION->flextable[$this->uniqueid] = new stdClass;
			$SESSION->flextable[$this->uniqueid]->uniqueid = $this->uniqueid;
			$SESSION->flextable[$this->uniqueid]->collapse = array();
			$SESSION->flextable[$this->uniqueid]->sortby   = array();
			$SESSION->flextable[$this->uniqueid]->i_first  = '';
			$SESSION->flextable[$this->uniqueid]->i_last   = '';
		}

		$this->sess = &$SESSION->flextable[$this->uniqueid];

		if(!empty($_GET[$this->request[TABLE_VAR_SHOW]]) && isset($this->columns[$_GET[$this->request[TABLE_VAR_SHOW]]])) {
			// Show this column
			$this->sess->collapse[$_GET[$this->request[TABLE_VAR_SHOW]]] = false;
		}
		else if(!empty($_GET[$this->request[TABLE_VAR_HIDE]]) && isset($this->columns[$_GET[$this->request[TABLE_VAR_HIDE]]])) {
			// Hide this column
			$this->sess->collapse[$_GET[$this->request[TABLE_VAR_HIDE]]] = true;
			if(array_key_exists($_GET[$this->request[TABLE_VAR_HIDE]], $this->sess->sortby)) {
				unset($this->sess->sortby[$_GET[$this->request[TABLE_VAR_HIDE]]]);
			}
		}

		// Now, update the column attributes for collapsed columns
		foreach(array_keys($this->columns) as $column) {
			if(!empty($this->sess->collapse[$column])) {
				$this->column_style[$column]['width'] = '10px';
			}
		}

		if(
			!empty($_GET[$this->request[TABLE_VAR_SORT]]) && $this->is_sortable($_GET[$this->request[TABLE_VAR_SORT]]) &&
			(isset($this->columns[$_GET[$this->request[TABLE_VAR_SORT]]]) ||
				(($_GET[$this->request[TABLE_VAR_SORT]] == 'firstname' || $_GET[$this->request[TABLE_VAR_SORT]] == 'lastname') && isset($this->columns['fullname']))
			))
		{
			if(empty($this->sess->collapse[$_GET[$this->request[TABLE_VAR_SORT]]])) {
				if(array_key_exists($_GET[$this->request[TABLE_VAR_SORT]], $this->sess->sortby)) {
					// This key already exists somewhere. Change its sortorder and bring it to the top.
					$sortorder = $this->sess->sortby[$_GET[$this->request[TABLE_VAR_SORT]]] == SORT_ASC ? SORT_DESC : SORT_ASC;
					unset($this->sess->sortby[$_GET[$this->request[TABLE_VAR_SORT]]]);
					$this->sess->sortby = array_merge(array($_GET[$this->request[TABLE_VAR_SORT]] => $sortorder), $this->sess->sortby);
				}
				else {
					// Key doesn't exist, so just add it to the beginning of the array, ascending order
					$this->sess->sortby = array_merge(array($_GET[$this->request[TABLE_VAR_SORT]] => SORT_ASC), $this->sess->sortby);
				}
				// Finally, make sure that no more than $this->maxsortkeys are present into the array
				if(!empty($this->maxsortkeys) && ($sortkeys = count($this->sess->sortby)) > $this->maxsortkeys) {
					while($sortkeys-- > $this->maxsortkeys) {
						array_pop($this->sess->sortby);
					}
				}
			}
		}

		// If we didn't sort just now, then use the default sort order if one is defined and the column exists
		if(empty($this->sess->sortby) && !empty($this->sort_default_column) && (isset($this->columns[$this->sort_default_column])
																				|| (in_array('fullname',$this->columns)
																					&& in_array($this->sort_default_column,
																								array('firstname','lastname')))))  {
			$this->sess->sortby = array ($this->sort_default_column => ($this->sort_default_order == SORT_DESC ? SORT_DESC : SORT_ASC));
		}

		if(isset($_GET[$this->request[TABLE_VAR_ILAST]])) {
			if(empty($_GET[$this->request[TABLE_VAR_ILAST]]) || is_numeric(strpos(get_string('alphabet'), $_GET[$this->request[TABLE_VAR_ILAST]]))) {
				$this->sess->i_last = $_GET[$this->request[TABLE_VAR_ILAST]];
			}
		}

		if(isset($_GET[$this->request[TABLE_VAR_IFIRST]])) {
			if(empty($_GET[$this->request[TABLE_VAR_IFIRST]]) || is_numeric(strpos(get_string('alphabet'), $_GET[$this->request[TABLE_VAR_IFIRST]]))) {
				$this->sess->i_first = $_GET[$this->request[TABLE_VAR_IFIRST]];
			}
		}

		if(empty($this->baseurl)) {
			$getcopy  = $_GET;
			unset($getcopy[$this->request[TABLE_VAR_SHOW]]);
			unset($getcopy[$this->request[TABLE_VAR_HIDE]]);
			unset($getcopy[$this->request[TABLE_VAR_SORT]]);
			unset($getcopy[$this->request[TABLE_VAR_IFIRST]]);
			unset($getcopy[$this->request[TABLE_VAR_ILAST]]);
			unset($getcopy[$this->request[TABLE_VAR_PAGE]]);

			$strippedurl = strip_querystring(qualified_me());

			if(!empty($getcopy)) {
				$first = false;
				$querystring = '';
				foreach($getcopy as $var => $val) {
					if(!$first) {
						$first = true;
						$querystring .= '?'.$var.'='.$val;
					}
					else {
						$querystring .= '&amp;'.$var.'='.$val;
					}
				}
				$this->reseturl =  $strippedurl.$querystring;
				$querystring .= '&amp;';
			}
			else {
				$this->reseturl =  $strippedurl;
				$querystring = '?';
			}

			$this->baseurl = strip_querystring(qualified_me()) . $querystring;
		}

		// If it's "the first time" we 've been here, forget the previous initials filters
		if(qualified_me() == $this->reseturl) {
			$this->sess->i_first = '';
			$this->sess->i_last  = '';
		}

		$this->currpage = optional_param($this->request[TABLE_VAR_PAGE], 0);
		$this->setup = true;

	/// Always introduce the "flexible" class for the table if not specified
	/// No attributes, add flexible class
		if (empty($this->attributes)) {
			$this->attributes['class'] = 'flexible';
	/// No classes, add flexible class
		} else if (!isset($this->attributes['class'])) {
			$this->attributes['class'] = 'flexible';
	/// No flexible class in passed classes, add flexible class
		} else if (!in_array('flexible', explode(' ', $this->attributes['class']))) {
			$this->attributes['class'] = trim('flexible ' . $this->attributes['class']);
		}

	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function get_sql_sort($uniqueid = NULL) {
		if($uniqueid === NULL) {
			// "Non-static" function call
			if(!$this->setup) {
			   return false;
			}
			$sess = &$this->sess;
		}
		else {
			// "Static" function call
			global $SESSION;
			if(empty($SESSION->flextable[$uniqueid])) {
			   return '';
			}
			$sess = &$SESSION->flextable[$uniqueid];
		}

		if(!empty($sess->sortby)) {
			$sortstring = '';
			foreach($sess->sortby as $column => $order) {
				if(!empty($sortstring)) {
					$sortstring .= ', ';
				}
				$sortstring .= $column.($order == SORT_ASC ? ' ASC' : ' DESC');
			}
			return $sortstring;
		}
		return '';
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function get_page_start() {
		if(!$this->use_pages) {
			return '';
		}
		return $this->currpage * $this->pagesize;
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function get_page_size() {
		if(!$this->use_pages) {
			return '';
		}
		return $this->pagesize;
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function get_sql_where() {
		if(!isset($this->columns['fullname'])) {
			return '';
		}

		$LIKE = sql_ilike();
		if(!empty($this->sess->i_first) && !empty($this->sess->i_last)) {
			return 'firstname '.$LIKE.' \''.$this->sess->i_first.'%\' AND lastname '.$LIKE.' \''.$this->sess->i_last.'%\'';
		}
		else if(!empty($this->sess->i_first)) {
			return 'firstname '.$LIKE.' \''.$this->sess->i_first.'%\'';
		}
		else if(!empty($this->sess->i_last)) {
			return 'lastname '.$LIKE.' \''.$this->sess->i_last.'%\'';
		}

		return '';
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function get_initial_first() {
		if(!$this->use_initials) {
			return NULL;
		}

		return $this->sess->i_first;
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function get_initial_last() {
		if(!$this->use_initials) {
			return NULL;
		}

		return $this->sess->i_last;
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function print_html() {
		global $CFG;

		if(!$this->setup) {
			return false;
		}

		$colcount = count($this->columns);

		// Do we need to print initial bars?

		if($this->use_initials && isset($this->columns['fullname'])) {

			$strall = get_string('all');
			$alpha  = explode(',', get_string('alphabet'));

			// Bar of first initials
		 
			echo '<div class="initialbar firstinitial">'.get_string('firstname').' : ';
			if(!empty($this->sess->i_first)) {
				echo '<a href="'.$this->baseurl.$this->request[TABLE_VAR_IFIRST].'=">'.$strall.'</a>';
			} else {
				echo '<strong>'.$strall.'</strong>';
			}
			foreach ($alpha as $letter) {
				if (isset($this->sess->i_first) && $letter == $this->sess->i_first) {
					echo ' <strong>'.$letter.'</strong>';
				} else {
					echo ' <a href="'.$this->baseurl.$this->request[TABLE_VAR_IFIRST].'='.$letter.'">'.$letter.'</a>';
				}
			}
			echo '</div>';

			// Bar of last initials

			echo '<div class="initialbar lastinitial">'.get_string('lastname').' : ';
			if(!empty($this->sess->i_last)) {
				echo '<a href="'.$this->baseurl.$this->request[TABLE_VAR_ILAST].'=">'.$strall.'</a>';
			} else {
				echo '<strong>'.$strall.'</strong>';
			}
			foreach ($alpha as $letter) {
				if (isset($this->sess->i_last) && $letter == $this->sess->i_last) {
					echo ' <strong>'.$letter.'</strong>';
				} else {
					echo ' <a href="'.$this->baseurl.$this->request[TABLE_VAR_ILAST].'='.$letter.'">'.$letter.'</a>';
				}
			}
			echo '</div>';

		}

		// End of initial bars code

		// Paging bar
		if($this->use_pages) {
			print_paging_bar($this->totalrows, $this->currpage, $this->pagesize, $this->baseurl, $this->request[TABLE_VAR_PAGE]);
		}

		if (empty($this->data)) {
			print_heading(get_string('nothingtodisplay'));
			return true;
		}


		$suppress_enabled = array_sum($this->column_suppress);
		$suppress_lastrow = NULL;
		// Start of main data table

		echo '<table'.$this->make_attributes_string($this->attributes).'>';

		echo '<tr>';
		foreach($this->columns as $column => $index) {
			$icon_hide = '';
			$icon_sort = '';

			if($this->is_collapsible) {
				if(!empty($this->sess->collapse[$column])) {
					// some headers contain < br/> tags, do not include in title
					$icon_hide = ' <a href="'.$this->baseurl.$this->request[TABLE_VAR_SHOW].'='.$column.'"><img src="'.$CFG->pixpath.'/t/switch_plus.gif" title="'.get_string('show').' '.strip_tags($this->headers[$index]).'" alt="'.get_string('show').'" /></a>';
				}
				else if($this->headers[$index] !== NULL) {
					// some headers contain < br/> tags, do not include in title
					$icon_hide = ' <a href="'.$this->baseurl.$this->request[TABLE_VAR_HIDE].'='.$column.'"><img src="'.$CFG->pixpath.'/t/switch_minus.gif" title="'.get_string('hide').' '.strip_tags($this->headers[$index]).'" alt="'.get_string('hide').'" /></a>';
				}
			}

			$primary_sort_column = '';
			$primary_sort_order  = '';
			if(reset($this->sess->sortby)) {
				$primary_sort_column = key($this->sess->sortby);
				$primary_sort_order  = current($this->sess->sortby);
			}

			switch($column) {

				case 'fullname':
				if($this->is_sortable($column)) {
					$icon_sort_first = $icon_sort_last = '';
					if($primary_sort_column == 'firstname') {
						$lsortorder = get_string('asc');
						if($primary_sort_order == SORT_ASC) {
							$icon_sort_first = ' <img src="'.$CFG->pixpath.'/t/down.gif" alt="'.get_string('asc').'" />';
							$fsortorder = get_string('asc');
						}
						else {
							$icon_sort_first = ' <img src="'.$CFG->pixpath.'/t/up.gif" alt="'.get_string('desc').'" />';
							$fsortorder = get_string('desc');
						}
					}
					else if($primary_sort_column == 'lastname') {
						$fsortorder = get_string('asc');
						if($primary_sort_order == SORT_ASC) {
							$icon_sort_last = ' <img src="'.$CFG->pixpath.'/t/down.gif" alt="'.get_string('asc').'" />';
							$lsortorder = get_string('asc');
						}
						else {
							$icon_sort_last = ' <img src="'.$CFG->pixpath.'/t/up.gif" alt="'.get_string('desc').'" />';
							$lsortorder = get_string('desc');
						}
					} else {
						$fsortorder = get_string('asc');
						$lsortorder = get_string('asc');
					}
					$this->headers[$index] = '<a href="'.$this->baseurl.$this->request[TABLE_VAR_SORT].'=firstname">'.get_string('firstname').get_accesshide(get_string('sortby').' '.get_string('firstname').' '.$fsortorder).'</a> '.$icon_sort_first.' / '.
										  '<a href="'.$this->baseurl.$this->request[TABLE_VAR_SORT].'=lastname">'.get_string('lastname').get_accesshide(get_string('sortby').' '.get_string('lastname').' '.$lsortorder).'</a> '.$icon_sort_last;
				}
				break;

				case 'userpic':
					// do nothing, do not display sortable links	  
				break;

				default:
				if($this->is_sortable($column)) {
					if($primary_sort_column == $column) {
						if($primary_sort_order == SORT_ASC) {
							$icon_sort = ' <img src="'.$CFG->pixpath.'/t/down.gif" alt="'.get_string('asc').'" />';
							$localsortorder = get_string('asc');
						}
						else {
							$icon_sort = ' <img src="'.$CFG->pixpath.'/t/up.gif" alt="'.get_string('desc').'" />';
							$localsortorder = get_string('desc');
						}
					} else {
						$localsortorder = get_string('asc');  
					}
					$this->headers[$index] = '<a href="'.$this->baseurl.$this->request[TABLE_VAR_SORT].'='.$column.'">'.$this->headers[$index].get_accesshide(get_string('sortby').' '.$this->headers[$index].' '.$localsortorder).'</a>';
				}
			}

			if($this->headers[$index] === NULL) {
				echo '<th class="header c'.$index.$this->column_class[$column].'" scope="col">&nbsp;</th>';
			}
			else if(!empty($this->sess->collapse[$column])) {
				echo '<th class="header c'.$index.$this->column_class[$column].'" scope="col">'.$icon_hide.'</th>';
			}
			else {
				// took out nowrap for accessibility, might need replacement
				if (!is_array($this->column_style[$column])) {
					// $usestyles = array('white-space:nowrap');
					$usestyles = '';
				 } else {
					// $usestyles = $this->column_style[$column]+array('white-space'=>'nowrap');
					$usestyles = $this->column_style[$column];
				 }
				echo '<th class="header c'.$index.$this->column_class[$column].'" '.$this->make_styles_string($usestyles).' scope="col">'.$this->headers[$index].$icon_sort.'<div class="commands">'.$icon_hide.'</div></th>';
			}

		}
		echo '</tr>';

		if(!empty($this->data)) {
			$oddeven = 1;
			$colbyindex = array_flip($this->columns);
			foreach($this->data as $row) {
				$oddeven = $oddeven ? 0 : 1;
				echo '<tr class="r'.$oddeven.'">';

				// If we have a separator, print it
				if($row === NULL && $colcount) {
					echo '<td colspan="'.$colcount.'"><div class="tabledivider"></div></td>';
				}
				else {
					foreach($row as $index => $data) {
						if($index >= $colcount) {
							break;
						}
						$column = $colbyindex[$index];
						echo '<td class="cell c'.$index.$this->column_class[$column].'"'.$this->make_styles_string($this->column_style[$column]).'>';
						if(empty($this->sess->collapse[$column])) {
							if($this->column_suppress[$column] && $suppress_lastrow !== NULL && $suppress_lastrow[$index] === $data) {
								echo '&nbsp;';
							}
							else {
								echo $data;
							}
						}
						else {
							echo '&nbsp;';
						}
						echo '</td>';
					}
				}
				echo '</tr>';
				if($suppress_enabled) {
					$suppress_lastrow = $row;
				}
			}
		}

		echo '</table>';

		// Paging bar
		if($this->use_pages) {
			print_paging_bar($this->totalrows, $this->currpage, $this->pagesize, $this->baseurl, $this->request[TABLE_VAR_PAGE]);
		}
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function add_data($row) {
		if(!$this->setup) {
			return false;
		}
		$this->data[] = $row;
	}

	/**
	 * @todo Document
	 * @return type?
	 */
	function add_separator() {
		if(!$this->setup) {
			return false;
		}
		$this->data[] = NULL;
	}
	
	/**
	 * Add a row of data to the table. This function takes an array with 
	 * column names as keys. 
	 * It ignores any elements with keys that are not defined as columns. It
	 * puts in empty strings into the row when there is no element in the passed
	 * array corresponding to a column in the table. It puts the row elements in
	 * the proper order.
	 * @param $rowwithkeys array
	 * 
	 */
	function add_data_keyed($rowwithkeys){
		foreach (array_keys($this->columns) as $column){
			if (isset($rowwithkeys[$column])){
				$row [] = $rowwithkeys[$column];
			} else {
				$row[] ='';
			}
		}
		$this->add_data($row);
	}

}

?>
